The present invention relates to carbon nanotubes, and more specifically, to a method of depositing carbon nanotubes on a substrate.
Nanotechnology, such as carbon nanotube (CNT) technology, has proven to be effective in addressing the ongoing trend of reducing the size of semiconductor devices. In particular, nanotube-based transistors, also known as carbon nanotube field-effect transistors (CNTFETs), are capable of digital switching. Various CNT placement techniques have been developed for depositing carbon nanotubes on a substrate to form the nanotube-based transistor. These CNT deposition techniques rely on substrate patterning, chemical surface functionalization, Langmuir-Blodgett-type techniques, or a combination thereof. However, the traditional CNT deposition techniques offer little control over the position, orientation, and density of the carbon nanotubes.
Another known technique for depositing carbon nanotubes on a substrate is based on dielectrophoresis, also known as the electric-field method. The conventional electric-field method requires the presence of metallic electrodes to induce an electric field at a desired location at which to dispose the carbon nanotubes. The presence of the metallic electrodes, however, deteriorates the functionality and performance of semiconductor devices after placement of the carbon nanotubes is complete. Further, maintaining embedded metal electrodes in the substrate prevents reducing the overall size of the semiconductor device.